Can two prepositions be used one after the other? [closed]
I am in doubt about my sentence. I am trying to describe around 73% accuracy that can be obtained using a mentioned method. So, I have written:
The study of Sen et al (2012) has shown that a tree canopy can be detected with about 73% overall accuracy.
Can I use with about together, one after the other?
There's nothing wrong with what you've written. In that context, about is not a preposition, but an adverb, meaning approximately.
There are other usages where consecutive prepositions are acceptable, too. For example, sometimes prepositions can build on each other, as in:
- He went up over the hill.
or when one preposition is used as part of an idiom or phrasal verb:
What did you have to bring that up for?
The oven will cool down after we shut it off.
You can certainly write with about 73% accuracy without violating any grammar rules. However, the sentence is awkward and needs rephrasing.
Some suggestions for writing better sentences in this kind of academic paper.
(A) Don't cite author names unless they and their work are extremely well known and using their names adds background value to your sentence. The bibliography or reference list is where author names belong.
(B) If you're discussing many authors and need to sort out who said what, then, of course, you must use author names, no matter how well known or unknown they are. And if you want to point out that your results and findings disagree with those in another study, then you need to mention the authors' names.
(C) Instead of saying "The study of Sen et al (2012) has shown...", you can eliminate a bit of verbosity by saying only Sen et al (2012) {have shown / showed / reported [CHOOSE ONE]}....
(D) I don't understand that tree canopy can be detected with about 73% overall accuracy. The definite article is missing between that and tree. Does this refer to leaf area index (LAI, leaf area per unit ground area)? If so, then the sentence should read something like this:
(E) Sen et al (2012) have shown that the leaf area index (LAI) of the tree canopy can be estimated with about 73% overall accuracy.
(F) The leaf area index (LAI) of the tree canopy can be estimated with about 73% overall accuracy (Sen et al, 2012) is shorter and also possible, but it might not be appropriate for the style of the paragraph.
(G) Eliminate all unnecessary words! I cut five words from your original sentence and added six (leaf area index (LAI) of the) that do work because they provide additional information. If those six extra words are unnecessary, then the final sentence is 25% shorter than the original. Be kind to your readers and delete useless verbiage.